Driving mechanism



Deg. 16, 1930. N. A. STRAND 1,785,055 DRIVING MECHANISYM Filed Oct 15 1928 Jfiveniorf Patented Dec. 16, 1930 UNITED STATES 1 The invention relates generally to driving mechanism and more particularly to that mechanism which is in 1 the form of an' attachment for an electric motor and embodies 5 a countershaft and a pulley-and-belt connection between the rotor shaft of the motor and said countershaft whereby the latter isdriven at a higher speed than the former, and in I which the frame for supporting the counter- ,10 shaft and the driven pulley is adjustably mounted above the motor so that the belt may be rendered taut and removed or shifted i with respect to the driving pulley on the rotor shaft and the countershaft is connected to drive a flexible shaft which in-turndrives at high speed a grinder wheel or drill. I

Heretofore in thistype of driving mechanism it has been the practice to employ but one countershaft andto support this shaft by a fork which constitutes the essential orprimary part of the pulley-frame and'consists of a pair of longitudinally spaced de pending fork-forming members which straddle the driven pulleyand have their lower L ends shaped to' form bearings for the ends of the countershaft. With an arrangement vof this character it is manifest that the speed ratio of the countershaft and rotor shaft cannot be exceedingly large and that the belt can only be removed from the driven pulley by first sliding the countersha'ft axially out i of engagement with the hearings in the" fork and vthenmoving the driven pulley so that t p latter to be removed; or disconnected from One object of the present inventionis to" it is free from the fork-forming members.

provide a driving mechanisnrof the type under consideration, which is of a unitary character and permits the countershafti to be drivenat a comparatively high speed. or

' 49 speed ratio by the employment of an inter; mediate counterslraft whichis driven from.

the rotor shaft of the motorby a belt-and i pulley connection and is/connected' to drive V the countershaft'fer the flexible. shaft by'ra secondbelt and-pulley connection.v

' Another object of the invention is the provision of 'a pulley-frame which permits thebelt-v between the two .countershaftshs well as the belt between the intermediate counter shaft and the rotor shaft to be disconnected and improved construction and in which fawithan electric motor M and forms thein- 1,18 PATIENT OFFICE for repair or displacement purposes without the necessity of disturbing either of, the countershafts or the parts associated therewith p A further object of'the invention is to pro- 5 vide a driving. mechanism which is ofnew cility ofadjustment and variability of action of the various partsare combined with dura bility and compactness of construction.

Other objects .will be apparent from a coniideration of the following detailed descrip- 10D. 1

The invention consists in the several novel features hereinafter set forth and more particularly defined by the claims at the conclusion hereof. a i In the drawing which-accompanies and.- forms apart of this specification" or disclosure and in which like numerals of ref- 7 erence denote corresponding parts throughout the several views: g F r Figure 1 is a side elevational view of an electric motor provided with a driving mechanism embod 1n the invention, a portion of 7 said mechamsnr ing' shown in section for purposes ofillustrationg g v Figure 2 is a detail sectional view illustrating the connection which errnits the ulley on thecountershaft for t e flexible aft to be adjusted relatively to the pulley on the intermediatecountershaft for the purposes of rendering the belt taut or permitting .the

the pulley-frame; i r V r c Figure is a section -taken, on the line 3-3 of F1 re 1, showin the manner in which the-adi usting stud or the pulley-framei-is finedly secured to. the motor'bracket' and 4 Figure 4 isal ngitudinal section of that portion of the \illey-frame which supports the countersha for the flexible shaft. The invention"is' exemplified in a mechanism which is adapted'to be associa I strunieiitality whereby power: from said mo tor isctransmitted to rotated flexible shaft S. ;',The distal end of the latterjtnot shown in the drawin' "is provided with a tool holder-into which may be fitted'a-grinder wheel, a drill or any other similar tool, as well understood in the art. The motor M may be of any suitable or standardconstruction that is commonly used in connection with apparatus of this character, and is shown as comprising a substantially cylindrical casing m and a rotor shaft 111. which extends'through the casing and is journaled in bearings m. The motor M may be moun ed or supported inany suitable manner, ch, for example, as by a suspension cable or upon a.b'ench B at the top of a swivelcolumn C.

.The driving mechanism which forms the 15 subject matter of the present invention is in t the nature of an attachment for the electric motor M and comprises an elongated bracket 5 which is adapted to be secured rigidly to the'top of the motorcasing m by a plurality of machine screws 6 or other like securing devices. The rear end of the bracket 5 forms a rest upon which is secured an electrical control switch .m for themotor. A split collar 7 is formed integrally withthe front end of said bracket 5 and has positioned therein the lower end of a vertically extending adjusting stud 9. screw 10 is operatlve to clamp the collar 7 around the adjusting stud so as to secure the latter fixedly in place with respect to the motorfbracket. This screw extends through a pair of lugs 11 and 12 which are formed integrally with the erid portions'of the column 7. The outer periphery of the adjusting stud 9 is provided with a screw thread 13.

The improved driving mechanism also comprises a pulley-frame which is prefer ably formed of bronze and consists of an upper member 14' and alower member .15. The lower member isfprovided. at its upper endwith a rearwardly extending lug 16. This lug has formed therein a vertically extending 'cylindricalsocket 17 throughwhich extendsthe adjusting stud 9. The socket.17 is .slightly larger in diameter than the ad justing stud so that the lug 16 may be slid up and down relatively to said stud to adjust the pulley-frame'vertlcally for purposes appearmg hereafter. The lug 16 rests 'upon'a nut 18 which is connected to the screw thread 13 and is rotatable-around the stud 9 so as to effect the desired vertical shift of the pulleyframe. To prevent the frame from rotating about the adjusting stud 9 during manipula tion of the nut 18 a screw 19 1s provided. This screw extends horizontally and into the rear end of the lug 16 and is provided at its inner end with a point orprojection 20 which fits in a vertical groove 21 in the rear part of the stud 9. The 'screw 19 is in the nature of a set screw and has a knurled head 19? at the rear end. When it is desired to elevate or lower the pulley-frame, the screw 20 is withdrawn sufliciently to avoid impingement of the point 20 against the stud 9. The nut tical adjustment, during which operation the point 20 slides in the groove 21 and prevents relative rotation of the. stud and pulley- '18 is then rotated to effect the desired verframe. The lower member 15 of the pulley 70 frame is provided with ahorizontally extending cylindrical hole 22 in which is journaled an intermediate countershaft 23. The front end of the latter is provided with a pulley 24 which comprises a hub 24 and is 7 fixedly secured to the countershaft by a set [screw 24? which passes thrOughsaid hub.

The pulley 24 is drivably connected by a belt 25 to a pulle 26 which is fixedly secured to the front en of the rotor shaft in.

er and smaller diameter than said pulley 26 so that the belt may be shifted from .one to another when it is desired to change the speed 5 of the intermediate countershaftu The latter is held against axial movement in its bearing by a cap orhead 23 which is connected to the rear end of the frame-member 15 by.

ascrew thread connectionand. bears against 90' The upper member 14 of the pulley-frame is in the form of an upwardly" extending fork and comprises a pair of vertical long1tudinally spaced -fork-forming members 29 and 30 which are connected together we at their lower ends by an integral connectmg member 31. The upperends of these fork-forming members are enlarged and drilled toform a pair of coaxial bearings 32 and 33.. A countershaft 34 is journaled in '105 these bearings and has fixedly secured to the central pottion thereof a pulley 35. This pulley extends :between the bearings 32 and 33 of the fork-forming members and is connected to be driven from the intermediate 0 countershaft bya belt 36which has its lower end looped around a pulley 37.' The latter is formed integrally with the pulley 24 and is contiguousto the front end of the lower member 15. The pulley 37 is larger in di- 115 ameter than'the pulleys 24 "and so that the countershaft 34 .is driven at a higher speed than the intermediate countershaft. The front end of the bearing 32 is provided with an integral forwardly projecting split '120 collar 38 having a screw 39 whereby 1t 15 'clamped around the shell or outercovering s f6r the flexible shaft S. An oil cup 40 is secured to the upper end of each bearing and is connected to deliver lubricant to the muntershaft 34. The latter is held against axial displacement by a head41 which is connected to the rear end of the bearing 33 by a screw ilhread connection and abuts against a shoulin said countershaft. The front end Pulleys and 28 are formedintegrally with the sides of the pulley 26 and are respectively ofa largclaims, without departing from of the countershaft 34 is hollow and is connected tothe flexible shaft S by a key or any other suitable means. f

. A The portion of the connecting member 31 5 which underlies the bearing 33 is provided with a depending spindle 42. This s indleis integral with the upper frame mem er 14 and fits within a split collar 43 which is formed integrally with and'p'rojects upwardly from the frame member 15. A screw 44 extends through ears or lugs 45 and 46 on the collar and is operative to clamp the collar around-the spindle. Said spindle and collar' exemplify means whereby the upper mem- 15 her may be adjusted vertically with respect to the lower member so that the belt 36 may be rendered taut br removed. A characteristic of utilizing two countershafts is that the flexible shaft may be drivenat a materially higher speed than the rotor shaft of the motor By forming the upper member of theframe so "that it extends upwardly, the belt, 36 may be removed-readily for'repair or replacement purposes without displacing or disturbing either of the countershafts, since it is only necessary to shift the frame-members 14 and 15 together, in which position the belt may be shifted forward out of engagement with the pulleys 35 and 37:.

a The operation of the driving mechan sm is as follows: When the motor Mjs actuated by proper manipulation of the switch m, the pulley 26 is rotated "and in turn drives the countersha 23 through the instrumentality of the belt 25and the pulley 24/ The 1dri ve movement of'the countershaft-23 is"-;- tra 1 mittedto-the countershaft 34 by the belt ,6 and the pulleys 35 and 37. In the event that the .belt 25 be omes worn and it is necessary to make the me taut'the pulley-frame is? raised by adjustingthe nut I8,'as previously .-desc ribed. Should it be desired toremove the belt 25 for replacement purposes thenut 18 will be rotated in the opposite direction so as to lowez the 'pulley-fram'e and permit- 7 the belt to be disconnected' from the-pulleys '24 and 26. The belt 36 is rendered'taut by the spindle and collar connection between the -u per member 14 and the lower 9- The driving mechanism he reih disclosed is ofa unitary character and is compact. It

consists of but a small number of parts and ,ma bemaniifactured at a low cost. V

7 e invention isnot to, beuhderstood a's restricted to,the de tails'set forth, since these maybe modified within the scope of the 23: e c fspi'rit and'scope of the inventiofi. I Having thus described the invention, what Iclaim as new'and desire to secure Letters Patent, is:

1. In driving mechanism (if the character described, the combination of a bracket pro- 63 vided with means wherebyitmaybe attached bracket and extending upwardly therefrom,

,with. a pair .of pulleys, a countershaft jour journaledin the lower member of said frame provided with a pulley frame, a belt between stud secured to the bracket and projecting mounted on the stud and comprising upper;

lthe upper ends of the fork-forming members to the top part-.of the of an electric motor, a stud secured to. one end of the a frame adjustably mounted on the stud and provided with a pair of countershafts arranged one above the other, a belt and pulley connection between the rotor shaft of the electric motor and the lower countershaft, and a J belt and pulley connection between the two co'untershafts. j L I 6 c v 2. In driving mechanism of the character described, the combination of a bracket adapted to be associated with an' electric I motor and providedw'ith attaching means, a stud secured to the'bra'cket and pro ecting up o wardly therefrom, a frame adj ustably mounted on the stud, a countershaftjournaled in the lower ortion of said frame and proyided .naled in the upper portion of the frame and provided with a pulley, a beltbetween the rotor. shaft of the electric moto r gind one of the. pulleys on the first mentioned countershaft, and a belt between the other pulley 3111161 fzhe pulley on the last mentioned counters a I 3. In, drivin mechanism of the character described, th combination of a bracket adapted to be associated with an electric motor and provided with attaching means, a stud secured to the bracket and projecting upwardly therefrom, a frame adjustably mounted on the stud and comprising upper and lpwer'members and adjustable connecting 'means therebetween, a countershaft and provided with a pair of pulleys, a countershaft journaled in the upper member and the rotor shaft of the electric motor and one of the pulleysion the countershaft associated with said lower member, and a belt between .the other pulley and the pulley on the coun tershaft associated with the upper ,framemember. 4. In; driving mechanism-of the cliaracter described. the combination of a bracket adapted to be associated with an electric" motor and provided with attaching means, a

fupwardly therefrom, ar fi-a-me adjustably and lower members and adjustable connect- ,-ing means therebetween, said upper-member bemg shaped to form'anup'wardly extending forkfa' countershaft 'journaled in the lower 'memberlof the frame and provided witha pair of pulleys, a countershaft ournaled'ii ofthe upper frame-member and provided, 1 with a pulley, a1 belt between the'rotor shaft of the electric motonand onegof the pulleys on the "countershaft in the lower member, and a-belt between the other pulley andthe pulley on 'the countershaft in the fork.

'- on the countershaft in t e fork I 0 Sifled at Chicago, Illinois, this 11th day of 5; In driving mechanism ofthe character described, the'combination of a bracket adapted to be associated with an electric motor andprovided with attaching means, a stud secured to the bracket and projecting upwardly therefrom, aframe comprisingv anupper member and a lower member, the lower member being provided at the upper end thereof with a split collar and a lug adjustably mounted on the stud, the uppermem: ber being shaped t0' form an upwardly xtending fork and havinga depending =spindle fitting within the collar, arc ountershaft ournaled in the lower member of the frame and p'rovided with a pair of pulleys, a countershaft journaled in the u per ends of the fork-formin members an provided with a pulley, a

ltbejtween the rotor shaft-of the electric motor and one-of thepulleys of the countershaft-in' the lower mem r, and a belt between the other ulleygand the pulley 5192 8. s 1 r v p 

